Improvement in the manufacture of fuel from coal dust and slack



UNITED STATES PATENT OFFICE.

WILLARD BROAD, OF ASHLAND, ASSIGNOR OF ONE-HALF HIS RIGHT TO CHARLES A.SHAW, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN THE MANUFACTURE OF FUEL FROM CQAL DUST AND SLACK.

Specification forming part of Letters Patent No. 150,393, dated May 5,1874; application filed I March 14, 1874.

To all whom it may concern:

Be it known that I, WILLARD BROAD, of

Ashland, in the county of Middlesex and State of Massachusetts, haveinvented a certain new and useful Improvement in Fuel, of which thefollowing is a description sufficiently full, clear, and exact to enableany person skilled in the art or science to which my inventionappertains to make and use the same.

My invention relates more especially to'that class of fuel which isusually pressed or formed into blocks for convenience in burning; andconsists in a composition made as hereinafter more fully set forth andclaimed, by which the finer particles of coal separated in screening areutilized, and an economical and freelyburning fuel produced.

The extreme simplicity of my invent-ion renders an elaborate descriptionunnecessary.

To prepare my improved fuel, I take unslaked lime or quicklime and slakeit in a solution consisting of ten gallons of water and two pounds ofcarbonate of soda, sufficient lime being used to form a thin paste.After the lime is fully slaked, and while warm, it is thoroughlyincorporated with ordinary coal screen.

ings or dust and formed into blocks of convenient size and shape foruse, enough only of the lime-paste being employed to cause the particlesof coal to adhere and form a mass. The blocks so formed are then driedin any convenient manner, after which they are ready for use, and may beburned in a grate or furnace in the same manner as ordinary fuel.

From the foregoing the nature and operation of my invention will bereadily understood by all conversant with such matters. The lime acts tohold the small lumps of coal and finer carbonaceous particles together,and also as a flux to promote combustion, while the soda not onlyintensifies the heat given out, but causes the fuel to burn with ahigh-colored and brilliant flame, rendering it well adapted to opengrates.

I do not confine myself to making the fuel thus formed into bricks anddrying them, as described, as it may be used in a plastic state orbefore it is dried, in connection with other fuel a ready ignited,without departing from the spirit of my invention. Neither do I confinemyself to the exact proportions given, as these may be variedconsiderably, according to the nature of the screenings used, and otherqualifying circumstances.

Having thus set forth my invention, what I claim is- The fuel described,consisting of a compound formed of coal-screenings mixed with limepaste,produced by slaking lime in a solution of soda, substantially as and forthe purpose specified.

Witnesses: WILLARD BROAD.

GEORGE T. HIGLEY, ALBERT LELAND.

